The purpose of this project is to revise and update The Utilization of Health Services: Indices and Correlates (Aday and Eichhorn, 1972). First, we will review the research literature from 1971-1979 to uncover new utilization studies. This task involves re-examining criteria for selecting articles, conducting a computerized as well as a more conventional bibliographic search, selecting the articles, and writing abstracts of these articles. Second, we will review the 207 abstracts presently included in the bibliography purging those that are dated, methodologically unsophisticated by today's standards, and irrelevant to current research and policy issues. Third, we will re-examine the typologies of indices and correlates of utilization that were employed in the 1972 bibliography, and add new measures and predictors of use that have entered the literature. We will also check trends in the use of services to spot changes and update findings on the correlates of use. The fourth objective of the research is to put the revised bibliography into a compterized format. This approach allows for better indexing and the development of a keyword system. It also simplifies the task of updating the bibliography in the future. The revised bibliography will serve as a starting point for researchers undertaking further studies of the use of health services and provide public officials and planners with a useful source of information when making decisions about the provision of health care.